You should be able to unplug the motor wire's - is it brushless or brushed-either way they should just pull apart-changing the shock tower isnt that hard-but the screw's holding it on can be a pain sometimes to get at depending how thick of a driver you are using. heres the part u need from RPM-lifetime warranty-but may wanna hold off from tower b/c their shipping would prob be as much as the part itself.

http://www3.towerhobbies.com/cgi-bin...&I=LXTDT1&P=ML

Here's an ebay listing w/ better price-i always use/bye stuff from this seller and get parts quick-

http://cgi.ebay.com/RPM-80832-Rear-S...item5adb39278b